The polyphenylene ether resins are a well-known family of linear thermoplastic engineering resins. A wide variety of these resins and a number of methods for their preparation are disclosed in Hay, U.S. Pat. Nos. 3,306,874 and 3,306,875, as well as in Stamatoff, U.S. Pat. Nos. 3,257,357 and 3,257,358.
It is a characteristic of the thermoplastic polyphenylene ether resins that they have a high viscosity in their molten state. This characteristic places a comparatively low limit on the rate at which the resins can be molded at safe temperatures in injection molding machines, and increases the power required to maintain a given rate of production from extrusion machines operating at a safe temperature. By "safe" is meant a temperature which does not cause depolymerization, oxidation or other degradation of the resin. Attempts have been made to employ organic compounds as viscosity depressants.